Rock Metamorphosis by Kinetic Energy

Robert G Bednarik

doi:10.28991/esj-2019-01192

Abstract

The objective of this work was to test the hypothesis that weathering-resistant surface layers found in intensively hammered petroglyphs at many sites worldwide and on other heavily battered metamorphosed rocks are the result of kinetic energy-induced tribological reactions. The methods of material testing included extensive fieldwork and in-situ studies at an Indian site that had been subjected to fluvial battery in the distant geological past; the removal of numerous surface and subsurface samples; and their analysis by several laboratory methods. These included binocular light microscopy, scanning electron microscopy, thin sectioning and elemental composition determination of crucial sites. It was confirmed that samples show evidence of crystallization by ductility of formerly amorphous silica cement in quartzite, yielding a tectonite of fully crystalline quartz. This finding confirms that the surficial application of very high levels of kinetic energy to certain rock types that are susceptible to metamorphosis can yield exceptionally weathering-resistant surface layers. This phenomenon has not been described before. Although it was first observed in rock art it is now thought to occur much more widely in numerous geological contexts, such as at fault mirrors, in the form of what has been regarded as glacial polish and on ventifacts.

Highlights

Introduced half a century ago [1], tribology is the science of interacting surfaces in relative motion [2]
Selected samples providing a complete sequence from the surface tectonite through to the unweathered quartzite were sectioned perpendicular to the surface and thin sections were produced
4-2- Effects of the KEM Process As noted above, in assessing the specific effects of the process causing kinetic energy metamorphosis of the quartzite’s non-crystalline silica components we focused on three criteria: the deposits forming the grain boundaries of the formerly amorphous silica zones, any residual sediments associated with this cement, and inclusions entrapped within quartz grains

Summary

Introduction

Introduced half a century ago [1], tribology is the science of interacting surfaces in relative motion [2]. It has applications in numerous fields, including in geology where it has, been largely ignored far. Mechano-chemical reactions can result in compounds or microstructures that differ from the products of ‘ordinary’ reactions. The relevance of tribology to tectonic phenomena is self-evident, but indications of tribological reactions occur on small scales in geology. They are the subject of this paper, introducing the phenomenon of kinetic energy metamorphosis (KEM)

Objectives

Methods

Conclusion